Excessive roaming in WLAN

[Bernhard_Voit]

Hi,
we have a WLAN with over 100 APs (37xx adn 38xx) in 3 Locations. V2110 as controllers with version 9.21.13.00005.
Recently we recognize some strange syslog entries regarding roaming behaviour:
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:34 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp028] FromAP[apgcp053] BSSID[D8:84:66:69:AD:C8] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
2016-11-24 15:43:49 Local1.Info controller1 events: EventType[Roam] MAC[34:14:5F:68:DE:6D] AP[apgcp053] FromAP[apgcp028] BSSID[D8:84:66:00:D0:18] Details: Inside AC from AP/Radio[2] to AP/Radio[2] VNS[SSID1]
This repeats als 15 seconds. All affected MACs are from Vendor 34:14:5F (Samsung electronics) and it only happens between a handful of our 122 APs. I dont know if this goes along with new devices or with the change of 36xx APs to 38xx.

Does anyone have seen this before or can explan it?

Thanks, Bernhard

[Bill_McIver]

Hello,
Do you know if load group "client balance" is configured? We can better understand this behavior if your able to provide more details about the VNS configuration and AP radio settings.
A strong case can be made for increasing "Min basic rate" setting on the radios. This will help with maintaining client/radio associations. Of course this is assuming RF coverage and overlaps aren't an issue. If these recommendations do not work out, please give GTAC a call for further assistance with this issue.

Thank you.

Bill McIver
Global Technical Assistance Center
Extreme Networks

[Bernhard_Voit]

We are not using Load Groups until now.
This behavor with rapidly roaming between APs only occoures in 2 of our VNS, which are both simple WPA-PSK with no Authentication. Both use the same topoligy (bridged at EWG).
I also configured "min basic rate" to 5.5 Mbps, Probe Suppression and Force Disassociate enabled and RSS Threshold to -75

[Peter_Kulmbrein]

I had some serious roaming issues with CAC (call admission control) activated with Spectralink devices - turning that feature off (WLAN Services-Qos-Global Admission Control) helped.

Perhaps that helps so far

[Bernhard_Voit]

Global Admission Control is not enabled on this VNS. Just WMM.